U.S. Pat. Nos. 5,013,806; 5,071,932; 5,077,365; and 5,071,932 (issued to Blevins and Turner in 1991) disclose copolymers of 4-vinyl-1,3-dioxolane with maleic anhydrides. Other than the compounds and processes described in these commonly-owned patents, no other known reference discloses copolymers of a 4-vinyl-1,3-dioxolane with maleic anhydride or its derivatives.
It is known that polymers containing maleic anhydride may be imidized to provide maleamic acids and that various chemical means are available to facilitate the ring closure of maleamic acids to form maleimides. However, we are aware of no references involving the polymerization of imidized derivatives of maleic anhydride with 4-vinyl-1,3-dioxolane.
While the copolymers of Blevins and Turner, supra, are useful, it would be desirable to have copolymers with improved properties such as greater resistance to moisture and hydrolysis.